The present disclosure relates generally to an arrangement for, and a method of, locating product tags associated with products in a venue, and, more particularly, to locating the product tags by locating users who are operating handheld, mobile readers for reading the product tags.
It is known to deploy a radio frequency (RF) identification (RFID) system in a retail, factory, or warehouse environment, or a like venue, for product locationing, product tracking, product identification, and inventory control. For example, in order to take an inventory of products associated with RFID product tags in a warehouse environment or venue, it is known to position a plurality of RFID tag readers at fixed, overhead locations in the venue, and then, to operate each such overhead reader, under the control of a network computer or host server, to transmit and receive RF signals over a relatively long, reading range, e.g., over twenty feet, to any such product tags to read their payloads. A multitude of product tags may be in the reading range of each reader. A specific location of any particular RFID-tagged product in the venue is typically determined by having the server process the payloads and capture data from a plurality of the overhead readers by using triangulation/trilateration techniques known in the art.
Although the known RFID system has been generally satisfactory, its performance could sometimes suffer and degrade when, for example, multiple RFID-tagged products are stacked closely together, thereby making any one individual product more difficult to isolate and read, and/or are positioned on metal shelving structures, or near walls, of the venue. In such cases, the RF signals are often reflected and/or scattered off these structures and walls along multiple paths, thereby reducing the capability of the readers of accurately locating the product tags. To help alleviate this performance degradation, handheld, user-operated, mobile, RFID tag readers are sometimes used in conjunction with the overhead RFID tag readers. The handheld, mobile readers typically have a shorter reading range, e.g., up to about ten feet, and since they can be brought more closely to, and targeted more directly at, individual products, a successful reading of each individual product is more likely, with a lesser likelihood that any RF signal will be reflected and/or scattered off walls and/or structures of the venue.
One drawback in using the handheld, mobile reader is that its location in the venue during reading of the product tags is not known, i.e., does not have a fixed position, and, therefore, although a product tag can typically be more accurately read by the mobile reader, the location of that product tag is likewise unknown. The art has proposed inferring the location of the product tag by locating the mobile reader. However, this requires the mobile reader to be specially configured and modified, and a special locationing system to be installed at the venue so that the modified mobile reader can be located and, in turn, so that the product tag and its associated product can be located relative to the mobile reader.
For example, it is known to deploy an ultrasonic locationing system in the venue for this purpose. The ultrasonic locationing system deploys a plurality of ultrasonic transmitters, e.g., speakers, preferably at fixed, overhead locations in the venue, and drives the speakers, under the control of the host server, to determine the location of any such mobile reader that contains an ultrasonic receiver, e.g., a microphone. Each ultrasonic speaker transmits an audio signal or ultrasonic energy in a short burst which is received by the microphone on the mobile reader, thereby establishing the presence and specific location of each mobile reader within the venue, again using triangulation/trilateration techniques known in the art. However, although the known ultrasonic locationing system has been generally satisfactory, its presence and installation add to overall system complexity and expense. In addition, the requirement to specially configure and modify the mobile reader also adds to system complexity and expense.
Accordingly, it would be desirable to reduce overall system complexity and expense, to avoid having to install and operate an additional locationing system such as an ultrasonic locationing system at a venue, to avoid having to specially configure and modify a mobile reader, and to accurately locate a product tag without having to first find the location of the mobile reader.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and locations of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The arrangement and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.